Photophysical properties of ternary rare earth (Sm3+, Eu3+) centered hybrids with N-heterocyclic modified Si–O bridge and terminal ligands

Abstract

5-Amino-1,10-phenanthroline (Phen-NH₂) is grafted to 3-(triethoxysilyl)-propyl isocyanate (TESPIC) to achieve the organic precursor Phen-Si, which is coordinated to rare earth ions (Sm³⁺ or Eu³⁺) and formed Si–O networks with tetraethoxysilane (TEOS) (Phen-Si-RE) after hydrolysis and polycondensation processes to obtain the hybrids Phen-Si-Ln. To investigate the influence of the second ligands to the photophysical properties of the hybrid material Phen-Si-RE, the organic ligand nicotinic acid (NA) and the polymers polyvinylpyrrolidone (PVP) (or PMMA) are further introduced into the above system to assemble the ternary hybrid materials Phen-Si-RE-NA and Phen-Si-RE-PVP (or Phen-Si-RE-PMMA), respectively. These hybrids are amorphous and especially the photophysical properties of them indicate that the introduction of the second ligands is favorable for the luminescence lifetime and quantum efficiency.